The present invention relates generally to recloser relays, and more particularly, to a controller for supervising the operation of a recloser relay.
Power circuit breakers are typically provided as a means for interconnecting or isolating portions of a transmission line. Such power circuit breakers are typically controlled by a monitoring system which, upon detection of an abnormal condition, commands the power circuit breaker to be appropriately opened or decoupled from the transmission line (tripped). Preferably, the power circuit breaker will remain in its open position until the abnormal condition is corrected or dissipates itself.
Typically, the dissipation of abnormal conditions is variable in nature. It is therefore generally desired that reclosure of the fault responsive circuit breaker be adaptable to the various types of fault conditions which may be encountered in a particular application. For example, in some applications it may be desired to issue a reclosure command to the circuit breaker without an intentional delay after the circuit breaker has been tripped. Such so called "instantaneous" reclosures would, of course, be subject to the inherent delays caused in operating the various components which are used to reclose the fault responsive circuit breaker. ln other applications it may be desired to intentionally delay such reclosure commands in order to permit time for the fault condition to dissipate. Often, it is desired to provide combinations of these commands to develop a progression of attempted reclosures which are timed to accommodate the various fault conditions which may arise in conjunction with the particular application involved.
To provide such capabilities, the recloser relays which are used to cause reclosure of the fault responsive circuit breaker are generally provided with the capability of performing a series of reclosure functions, the first generally being an instantaneous reclosure and the remaining reclosures generally incorporating progressively increasing time delays. In operation, such recloser relays would generally first attempt an instantaneous reclosure upon sensing a fault condition. If the reclosed circuit breaker remains closed for a prescribed reset period, a successful reclosure is deemed accomplished. If not, the recloser relay progresses through subsequent, delayed recloses in similar manner until either a successful reclose occurs or until the resulting reclose cycle is unsuccessfully completed, indicating a lockout condition and the need for manual intervention.
Typically, the timing of such a reclose cycle is regulated by a rotating cam shaft which operates in conjunction with associated, mechanically operated switches. Examples of such systems may be found in U.S. Pat. No. 3,381,177, issued to W. P. Allen, and U.S. Pat. Nos. 3,333,154 and 2,582,027, issued to L. E. Goff, Jr. Although providing adequate results in many applications, such mechanical systems present several limitations in their use, primarily due to the inherent limitations of the mechanically operated components comprising such systems. This often limits the ability of an operater to select when various reclosures are to occur with respect to a sensed fault, as well as to select the time delays associated with each attempted reclose and the reset time needed to safely assure that an attempted reclose has been successful. It is therefore desirable to perform the foregoing functions electronically, to remove such mechanical dependencies from the reclose cycle and to provide the reclose cycle with increased versatility.
Accordingly, it is a primary object of the present invention to provide a versatile means for monitoring and supervising the reclosing of a fault responsive circuit breaker so as to accommodate various fault conditions related to the associated transmission line.
It is a further object of the present invention to provide means for easily setting and varying the parameters of the reclose cycle which regulates the operation of a recloser relay associated with a fault responsive circuit breaker, to accommodate a variety of potential faults arising in conjunction with a transmission line.
It is a still further object of the present invention to provide an electronically derived means for regulating the operation of a recloser relay, to provide increased facility and versatility in setting and varying the parameters of the resulting reclose cycle.
It is a still further object of the present invention to provide an electronically derived means for regulating the operation of a recloser relay associated with a fault responsive circuit breaker which uses a limited amount of electronic devices to provide a simple, reliable, yet economical device.
These and still further objects will become apparent from the following description.